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ISSUES RESOLUTION MATRIX FOR FERNALD SITE PROFILE AND SEC PETITON

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TBD 7 The TBD does not 

specify a method for 

estimating doses in 

the raffinate streams, 

which are uraniumpoor, from ore 

processing in

Plant 2/3. These 

doses may be very 

difficult to calculate, 

especially for highgrade ores, notably 

pitchblende ore from 

Congo.

This also pertains to SEC Finding 4.2-2 and 

Primary SEC Issue 4: “Review of radon 

breath data for adequacy for reconstructing 

doses due to the inhalation of Ra-226 and

Th-230.”

October 14, 2008 – NIOSH responded:

NIOSH has radon breath analyses for 

raffinate transfer operations and air 

sample data in the Plant 2/3 raffinate 

handling area sufficient to bound possible 

intakes and allow claimant-favorable dose 

reconstructions of sufficient accuracy.

The NIOSH approach is contained in ORAUTRPRT-0052 (ORAUT 2011b). RPRT-0052,

pp. 24–25: Transfer of drummed K65 raffinate 

to Silos 1 and 2 late 1952–June 1953; radon 

breath data available. Q-11 transfer 1954–

1957; subsumed in SEC.

The concern for the raffinate streams can be 

bounded by the extensive “radon breath 

analyses-to-radium deposition” performed 

during the K-65 raffinate drum disposal 

operation. In addition, confirmatory air 

monitoring data in Plant 2/3 specific to the 

raffinate operations provides assurance that 

exposures are adequately bounded. The 

raffinates were wet (minimizing air 

contamination production) and enclosed in 

process piping.

Other uranium daughters in addition to Ra-226 

intake can be adequately bounded by ratioing 

to Ra-226, using the isotopic analyses of the 

silo contents.

A detailed discussion of SEC Issue 4 took 

place at the April 19, 2011, WG meeting 

(ABRWH 2011), where SC&A agreed that 

10/15/2013: SEC recommends this issue be 

changed to “in abeyance” pending revised 

TBD.

4/10/2014: New revision of ORAUT-TKBS0017-5 not yet available. October 2013 

recommendation holds.

8/25/2014: October 2013 recommendation 

holds.

11/18/2014: SC&A believes this issue is far too 

complex to be put in abeyance without a formal 

review. SC&A recommends that it be changed 

to “open” until we have an opportunity to 

review the revised internal dose portion of the 

Fernald site profile.

12/4/2014: This issue was discussed during 

work group deliberations and it was 

recommended this finding be put “in progress” 

while NIOSH develops methods for assessing 

dose to raffinates. (ABRWH 2014c, p. 149)

7/28/2017: This issue was discussed during 

Work Group deliberations. NIOSH’s 

position is that there is no exposure potential 

to uranium and radium-poor raffinates due 

to the nature of process equipment and 

physical form of the material. NIOSH is to 

provide an official written position on 

uranium and radium-poor raffinates 

exposure potential. SC&A recommends that 

the issue remain In Progress pending release 

of formal NIOSH position.

ORAUT-RPRT-0052, “Feed

Materials Production Center 

Internal Dose Topics,” 

provides a method for 

estimating raffinate streams, 

which will be incorporated 

into ORAUT-TKBS-0017-5,

“Technical Basis Document 

for the Fernald 

Environmental Management 

Project (FEMP) –

Occupational Internal Dose,” 

and ORAUT-TKBS-0017-4,

“Fernald Environmental 

Management Project –

Occupational Environmental 

Dose,” revisions.

ORAUT-OTIB-25,

“Estimation of Radium-226 

Activity in the Body from 

Breath Radon-222 

Measurements,” which is 

included in ORAUT-RPRT0052, provides a method for 

reconstructing doses from 

radon breath analyses results 

from 1952–1954 and this 

methodology will be included 

into the internal TBD 

revision.

10/24/2017: NIOSH’s 

position is that there was little 

potential for exposure to 

uranium- and radium-poor 

raffinates, since they were 

liquids that were pumped to 

disposal pits. If there were 

In 

Progress
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NIOSH’s methods were bounding and 

sufficiently accurate.

exposures to uranium- and 

radium-poor raffinates, doses 

from those exposures cannot 

be reconstructed with 

sufficient accuracy, given the 

information available to 

NIOSH. Any such exposures 

occurred within the period of 

the existing “thorium” SEC 

class. Therefore no further 

SEC action is required, and 

doses resulting from exposure 

to uranium- and radium-poor 

raffinates will not be 

included in partial dose 

reconstructions.

TBD 8 Workers who may 

have worked with 

raffinates may be 

missed by the 

protocol specified in 

Vol. 5 of the TBD. 

The guidelines for 

determining which 

workers were 

exposed to raffinate 

dusts are too 

restrictive and place 

far too great a 

reliance on 

completeness of 

records for job 

assignments, or in the 

alternative, place the 

burden of proof on 

the claimant. They 

have not been 

adequately justified 

by measurements and 

are not claimant 

favorable.

See response to Finding 7. 10/15/2013: See response to Finding 7.

11/18/2014: SC&A believes this issue is far too 

complex to be put in abeyance without a formal 

review. SC&A recommends that it be changed 

to “open” until we have an opportunity to 

review the revised Internal Dose portion of the 

Fernald site profile.

12/4/2014: This issue was discussed during 

Work Group deliberations and it was 

recommended this finding be put “in progress” 

while NIOSH develops methods for assessing 

dose to raffinates. (ABRWH 2014c, p. 149)

7/28/2017: This issue remains In Progress 

(see status details under Finding 7).

See NIOSH response 7. In 

Progress
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TBD 9 The data on trace 

contaminants in RU 

in the Fernald TBD 

are incomplete and 

appear to be 

incorrect. Different 

official documents 

have very different 

values for various 

aspects of RU data, 

including production 

and contamination. 

The contradictions 

have not been sorted 

out in the TBD.

This finding is the same as SEC Finding No. 

4.1-6. NIOSH responded as follows:

Some production data are admittedly 

conflicting. Since dose reconstruction does 

not depend directly on production data, 

sufficient data are available to enable a 

bounding estimate based on the ratio of RU 

contaminates to the uranium intake 

determined from the uranium urinalyses.

Recommended defaults have been chosen 

that adequately bound all of the 

operational data. The shipment(s) from 

Paducah Gaseous Diffusion Plant were of 

short duration, the increased hazards were 

recognized and adequately controlled, and 

recognized as doubling the total inventory 

of RU contaminants at FMPC, which in 

turn was factored into the default 

assumptions.

After many white paper exchanges and 

deliberations, NIOSH demonstrated that they 

could place a plausible upper bound on intakes 

from three principal RU constituents.

10/15/2013: SC&A recommends finding be 

changed to “in abeyance” pending revised 

TBD.

4/10/2014: New revision of ORAUT-TKBS0017-5 not yet available. October 2013 

recommendation holds.

ORAUT-RPRT-0052 (July 2011), Section 4.5,

Table 18 does not reflect agreed-upon 

constituent levels from WG discussions on 

February 9, 2012 [See SC&A white paper titled 

SC&A’s Response to NIOSH’s Subgroup 10A 

Impact Analysis Dated November 1, 2011 

(SC&A 2012a)].

Need to verify that what was agreed upon in 

WG meetings is, in fact, incorporated into 

ORAUT-TKBS-0017-5 and any related 

guidance documents.

8/25/2014: SC&A recommends that this 

finding be kept in abeyance pending revision of 

ORAUT-TKBS-0017-5.

11/18/2014: August 2014 recommendation 

holds.

12/4/2014: August 2014 recommendation 

holds. (ABRWH 2014c, p. 153)

7/28/2017: This issue was discussed during 

the Fernald WG meeting. NIOSH has 

revised its position on recycled uranium 

contaminant ratios for the period 1961–

1972. NIOSH is to provide an official written 

position on the revised ratios. Issue to 

change from “In Abeyance” to “In 

Progress.”

ORAUT-RPRT-0052, “Feed

Materials Production Center 

Internal Dose Topics” 

provides an upper bound on 

intakes from RU constituents, 

which will be incorporated 

into ORAUT-TKBS-0017-5,

“Technical Basis Document 

for the Fernald 

Environmental Management 

Project (FEMP) –

Occupational Internal Dose,” 

and ORAUT-TKBS-0017-4,

“Fernald Environmental 

Management Project –

Occupational Environmental 

Dose,” revisions.

10/24/2017: NIOSH’s use 

of the 10 ppb Pu in RU 

through 1972 is based on the 

lot data found in Attachment 

C of the Ohio Field Office 

Report (SRDB 003644). 

From a quick review of the 

lots identified as being 

processed prior to 1973, it 

appears that more than 95% 

of the identified Pu 

concentrations are below 1 

ppb. Of those that are above 

1 ppb Pu, most of those are 

still below 10 ppb Pu. This 

means that any potential to 

exposures to RU with Pu 

concentrations great than 10 

ppb would be considered 

rare and to be short in 

duration. The remaining 

and thus majority of any 

worker’s exposure time 

In 

Progress
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would have been associated 

with materials well below 

the recommended default 

level of 10 ppb Pu. 

Therefore, NIOSH cannot 

identify any reason to 

believe that any worker 

could have an exposure for 

which the recommended 

default level of 10 ppb Pu 

would not be adequately 

conservative and bounding.

TBD 11 The suggested 

approach for RU dose 

estimation in the 

TBD is claimant 

favorable for many 

RU workers, but not 

claimant favorable

for others and for 

some periods; it is not 

based on an 

evaluation of the 

available data.

This is similar to SEC Primary Issue 3.

After many white paper exchanges and 

deliberations, NIOSH demonstrated that they 

could place a plausible upper bound on intakes 

from the three principal RU constituents.

Subsumed into SEC pre-1979. Coworker 

model applicable 1979–1986 when WMCO 

took over M&O from NLO and for non-SEC 

claimants.

10/15/2013: SC&A recommends finding be 

changed to “in abeyance” until agreed upon 

method is incorporated into the TBD.

8/25/2014: SC&A recommends keeping this 

finding in abeyance pending upcoming revision 

to ORAUT-TKBS-0017-5.

11/26/2014: SC&A recommendation from 

8/25/2014 holds.

12/4/2014: This item was not discussed at the 

Work Group meeting. Recommendation from 

8/25/2014 holds.

7/28/2017: Issue to change from “In 

Abeyance” to “In Progress” (see status 

details under Finding 9).

ORAUT-RPRT-0052, “Feed

Materials Production Center 

Internal Dose Topics” 

provides an upper bound on 

intakes from RU constituents 

for all workers, which will be 

incorporated into ORAUTTKBS-0017-5, “Technical 

Basis Document for the 

Fernald Environmental 

Management Project (FEMP)

– Occupational Internal 

Dose,” and ORAUT-TKBS0017-4, “Fernald 

Environmental Management 

Project – Occupational 

Environmental Dose,” 

revisions.

10/24/2017: See NIOSH 

response details under 

Finding 9.

In 

Progress

SEC 

P

3 Default 

concentrations (on U 

mass basis) of

Pu-239, Np-237, and

other isotopes 

associated with RU at 

After many white paper exchanges and 

deliberations, NIOSH demonstrated that they 

could place a plausible upper bound on intakes 

from the three principal RU constituents.

10/15/2013: SC&A recommends issue be 

placed “in abeyance” until implemented in site 

profile.

4/10/2014: Recommend that related site profile 

issues be placed in abeyance. SC&A will need 

ORAUT-RPRT-0052, “Feed

Materials Production Center 

Internal Dose Topics,” 

provides an upper bound on 

intakes from RU constituents 

for all workers, which will be 

In 

Progress
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Fernald may not be 

bounding for some 

classes of worker 

activities, buildings, 

and time periods.

to review relevant TBD revisions to determine 

whether our concerns are adequately addressed. 

See response to Finding 9.

8/25/2014: SC&A recommends that this 

finding be kept in abeyance pending revision of 

ORAUT-TKBS-0017-5.

11/26/2014: August 2014 recommendation 

holds. However, note that only the three 

primary contaminants have been addressed and 

other radionuclides may be relevant to dose 

reconstruction (for example, Am-241 from 

Finding 10).

12/4/2014: Based on discussions occurring 

during the Work Group meeting, it was 

recommended this finding be changed from “in 

abeyance” to “in progress” pending NIOSH 

investigations into potential exposures to Am241 in recycled uranium. See also update to 

Finding 10. (ABRWH 2014c, pp 154–167).

7/28/2017: This item was discussed during 

the WG meeting. The issue of RU 

contaminant ratios is no longer an SEC 

issue. However, NIOSH has altered its 

approach to assignment of RU contaminants 

and is to provide an official written response 

on the issue. The WG recommends the issue 

remain “In Progress” pending development 

and discussion of NIOSH’s new position (see 

TBD Findings 9 and 11). The portion of this 

finding related to Am-241 has been 

recommended for closure (see TBD

Finding 10).

incorporated into ORAUTTKBS-0017-5, “Technical 

Basis Document for the 

Fernald Environmental 

Management Project (FEMP)

– Occupational Internal 

Dose,” and ORAUT-TKBS0017-4, “Fernald 

Environmental Management 

Project – Occupational 

Environmental Dose,” 

revisions.

10/24/2017: See NIOSH 

response details under 

Finding 9.

ThoriumWhitePaper

Th-4 Unless sufficient 

evidence exists that 

thorium exposure 

potential at Fernald 

was restricted to 

solubility class “W,” 

NIOSH should 

This issue was first discussed during the 

December 2014 Work Group meeting; 

however, no path forward was agreed upon at 

that time.

7/28/2017: This issue was discussed at the 

WG meeting. NIOSH is to reconsider the 

assumed solubility class for application of 

10% DAC values used in unmonitored 

thorium dose reconstruction (1990–1994). 

NIOSH to provide official written position 

on issue. WG recommends finding be 

It is standard industry 

practice to utilize the more 

restrictive DAC value for the 

purposes of controlling 

airborne contamination.

Therefore, the lower class W 

DAC is appropriate.

In 

Progress
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consider using the 

more conservative 

and claimant 

favorable DAC value 

for solubility class 

“Y.”

designated as In Progress.

10/24/2017: SRDB Ref. ID# 

4152, “Radiological Air 

Sampling Program and Air 

Sampling Philosophy,” 

(February 1989) indicates 

that Fernald applied the class 

W thorium DAC for 

controlling airborne activity 

areas. This document 

identifies areas where 

thorium was present and 

states for each that the class 

W DAC shall be used or is 

in effect. Therefore, the 

usage of 10% DAC for Class 

W Th-232 in Table 5-40 is 

appropriate for the 

assignment of unmonitored 

thorium intakes in 1990-

1994.

Reference to SRDB Ref. ID 

4152 and supporting text has 

been incorporated into 

Section 5.5.2.3.2 of the 

current working draft of 

ORAUT-TKBS-0017-5, 

Rev. 04.

ThoriumWhite

PaperTh-6 The underlying 

assumptions 

employed to 

reconstruct doses to 

thoron appear to be 

arbitrary and are not 

well established or 

referenced. The 

assumptions 

concerning thorium 

source term 

inventory, release 

This issue was first discussed during the 

December 2014 Work Group meeting; 

however, no path forward was agreed upon at 

that time. Appendix B to the Fernald internal 

dose TBD contains a discussion of SC&A’s 

concerns.

7/28/2017: This issue was discussed at the 

WG meeting. NIOSH is to consider 

modeling Building 65 thoron doses 

specifically. In addition, NIOSH is to 

provide an official position on assumed 

occupancy factors for thoron exposure. The 

WG recommends that this finding be 

designated as In Progress.

—

10/24/2017:

NIOSH response presented 

below.

In 

Progress
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fraction, equilibrium 

factor, occupancy 

time, and specific 

activity of thoron 

should be more 

carefully defined 

based on credible 

documentation and 

site-specific records.

10/24/2017:

1. The following information provides a better explanation of how default values for thoron exposure in storage facilities are estimated:

The highest FMPC thoron exposures are likely to be associated with storage facilities because the mass of material in storage exceeds the amount in process daily. Large scale 

storage operations are typically occupied only a fraction of the work day. Ventilation in storage facilities is likely to be at a lower air change rate when compared to ventilation in a 

processing facility where vigorous mechanical or chemical processes are conducted. ORAUT-TBKS-017-5, Rev 3, Table B-5 “Summary of thoron exposure estimates” shows, in 

the last two rows various storage sites throughout the site’s history contained as much as 300 MT (300*106 g) of thorium. Using a value of 0.989*105 pCi/g, there could be 3*1013

pCi of Th-232 in storage. 

The thorium in storage was chemically purified at some time prior to storage. That created a disequilibrium between Th-232 activity and Th-228 activity, which would be a 

variable as a function of time, initially decreasing and then increasing several years later. The time since chemical separation is not known, but the assuming only one chemical 

separation occurred the disequilibrium cannot be less than 65%, or more than 100%. Since 100% is a bounding assumption, that value is selected. It follows that the bounding 

activity of Th-228 in storage, and its short-lived the decay product, thoron, will be 3*1013 pCi.

A release fraction for the thoron in storage must be assumed. Release of the inert noble gas thoron under storage conditions occurs by a diffusion process. The short half-life of 

thoron (56 s) limits the amount of diffusion that can occur before the element loses its noble gas property and diffusion stops. This means that release fractions for material in 

storage tend to be small. Assuming a relatively large release fraction value of 1*10-4, the airborne thoron activity in a large storage facility is 3*108 pCi. The estimated volume of 

the airspace in an FMPC storage building is 1*107 L, so the thoron air concentration is 300 pCi/L. 

The Potential Alpha Energy Concentration (PAEC) described in Table B-3 shows that there is 1.33*105 MeV/L per 7.5 pCi/L of thoron. PAEC can be expressed in Working Level, 

where 7.5 pCi of thoron in equilibrium with the short-lived decay products equals one Working Level. A 300 pCi/L concentration of thoron in equilibrium with its short-lived 

decay products is 40 WL. 

In a 2006 paper, Harley and Chittaporn reported that the indoor thoron equilibrium factor, Feq, is likely to be 0.02 and cannot exceed 0.04. Feq describes the activity relationship 

between thoron and its short-lived decay products which contribute to respiratory tract dose. Feq can be used as a factor to modify Working Level. Using a value of Feq of 0.04, the 

Working Level is 0.16. Assuming an occupancy factor in the storage facility of 25% (three work months per work year) the thoron exposure potential is 0.4 WLM per year.

2. The following information provides a better explanation of how default values for thoron exposure in Building 65 is estimated:
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A thoron concentration of 267 pCi/L was measured in Building 65 during the first calendar quarter of 1996 as reported in Renk (1998, page 65, SRDB Ref ID: 133254) using a 

track-etch device. This was by far the highest reported result in that large data set. Although it is an outlier in the context of the average measurement for that period at FMPC, it 

probably is an accurate indicator of the thoron concentration in that building. 

The Potential Alpha Energy Concentration (PAEC) described in Table B-3 shows that there is 1.33*105 MeV/L per 7.5 pCi/L of thoron. PAEC can be expressed in Working Level, 

where 7.5 pCi of thoron in equilibrium with the short-lived decay products equals one Working Level. A 267 pCi/L concentration of thoron in equilibrium with its short-lived 

decay products is 35.6 WL. 

In a 2006 paper, Harley and Chittaporn reported that the indoor thoron equilibrium factor, Feq, is likely to be 0.02 and cannot exceed 0.04. Feq describes the activity relationship 

between thoron and its short-lived decay products which contribute to respiratory tract dose. Feq can be used as a factor to modify Working Level. Using a value of Feq of 0.04, the 

Working Level is 1.42. Assuming an occupancy factor in the storage facility of 25% (three work months per work year) the thoron exposure potential is 0.36 WLM per year.

Considering that this measured value represented only one calendar quarter out of many, it is unlikely that this is a bounding analysis of the thoron exposure potential in Building 

65. A bounding analysis might be expected by increasing the thoron exposure by 50%. This results in a rounded value of 0.5 WLM per year.

3. The value used to describe the disequilibrium between Th-232 and Th-228 could be any number less than 100%. Triple-separated thorium, with its equilibrium value of 23%, was 

selected for use when interpreting in vivo lung counting data because in that context a lower value is more favorable to the claimant than a higher value. In the context of thoron 

exposure based on air concentration of radioactive material, a higher equilibrium value is more favorable. For this calculation a value of 100% is chosen as a bounding and 

claimant-favor assumption.

4. The value, Feq, used to describe the equilibrium between thoron (Rn-220) and its short-lived decay products is used to modify the Working Level calculated with the assumption of 

100% equilibrium. Values of Feq could range from less than 1% to 100%. Higher thoron exposures result from higher values of Feq. Empirically, Feq has been observed to be very 

low, only a few percent. In a 2006 paper, Harley and Chittaporn reported on the indoor thoron equilibrium factor and included data from FMPC in the analysis. They concluded 

that 0.04 was a bounding value.

5. A release fraction for the thoron from solid thorium metal or sol-gel must be assumed. Release of the inert noble gas thoron under storage conditions occurs by a diffusion process. 

The short half-life of thoron (56 s) limits the amount of diffusion that can occur before the element loses its noble gas property and diffusion stops. This means that release 

fractions for material in storage tend to be small. We believe that a bounding value for this factor is 1*10-4. When this value is assumed the thoron exposure calculated in item 1 

(above) matches well with the empirically observed thoron exposure shown in item 2 (above). 

6. The thoron exposure for the “Passive storage” period, 1986 through 1987, will be changed to match the thoron exposure assigned during the “Long-term DOE repository storage” 

period. 

7. In summary, we recommend that 0.5 WLM/y can be used as a bounding estimate of thoron exposure for all years and all locations for those claimants who are potentially exposed.